Multistage separation system

ABSTRACT

A “bolt on” static separator is disclosed for use in conjunction with a rotating separator to handle higher liquid volumes that are not able to be effectively separated by the rotating separator alone. The static separator may be positioned upstream of the rotating separator, generally right in front of the rotating separator, i.e., immediately ahead of the inlet to the rotating separator and generally attached directly to the front end of the rotary separator. The static separator may include a significant change in flow path direction that is sufficient to cause coarse fluid separation. The output of the static separator is in communication with the input of the rotating separator. Additionally, the drain of the static separator is in communication with the drain of the rotating separator and is at the same pressure.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a divisional of U.S. Utility patent application Ser.No. 14/066,198, which was filed on Oct. 29, 2013, which is acontinuation of U.S. Utility patent application Ser. No. 13/171,259,which was filed Jun. 28, 2011, now U.S. Pat. No. 8,580,002, which claimsthe benefit of U.S. Provisional Patent Application Ser. No. 61/362,842,which was filed Jul. 9, 2010. The entirety of these priorityapplications are incorporated herein by reference to the extentconsistent with the present disclosure.

BACKGROUND

In compression systems, a multiphase fluid stream is typically separatedinto gas and liquid phases prior to compression, as compressors suitablefor a gaseous compression are oftentimes not configured to effectivelyprocess the liquid portion of a multiphase fluid stream. As such, afluid separation system configured to remove the liquid portion of themultiphase fluid stream is generally positioned upstream of thecompression system, such that the inlet stream to the compression systemis substantially free of fluids. A typical fluid separation system usedin this scenario includes a rotating drum-type system that uses arotating drum to generate sufficient force to physically cause the fluidportion of the multiphase stream to be separated from the gas portion ofthe stream. However, in many compression systems, the multiphase fluidarrives at an inlet of the rotary separator containing a higher volumeor percentage of fluid than the rotary separator is capable ofseparating. As such, a larger rotary separation system is required,which substantially increases the complexity and cost (initial equipmentand ongoing maintenance) of the system.

As such, there is a need for a simple, efficient, and cost effectivesolution to allow smaller and less expensive rotary separators toeffectively handle higher volume liquid separation.

SUMMARY

Embodiments of the disclosure may provide a “bolt on” static separatorthat is used in conjunction with a rotating separator to handle higherliquid volumes that are not able to be effectively separated by therotating separator alone. The static separator may be positionedupstream of the rotating separator, generally right in front of therotating separator, i.e., immediately ahead of the inlet to the rotatingseparator and generally attached directly to the front end of the rotaryseparator. The static separator may include a significant change in flowpath direction that is sufficient to cause coarse fluid separation. Theoutput of the static separator is in communication with the input of therotating separator. Additionally, the drain of the static separator isin communication with the drain of the rotating separator and is at thesame pressure.

In another embodiment of the disclosure, a multistage separation systemis provided. The system may include a rotating shaft driving amultistage compressor, a rotating fluid separation system attached tothe rotating shaft with an output of the rotating fluid separationsystem communicating with an input of the multistage compressor, and astatic separation curve positioned upstream of the fluid separationsystem such that an output of the separation curve feeds an inlet of thefluid separation system, the separation curve being at least partiallypositioned radially outward of the fluid separation system.

Another embodiment of the disclosure may provide a combined static anddynamic separation system. The system may include a driven centrifugalcompressor having a central rotating shaft, a rotating separationsection comprising a rotating fluid separation drum attached to therotating shaft for concomitant rotation therewith, and a staticseparation section positioned immediately upstream of the rotatingseparation section such that an output of the static separation sectionis in fluid communication with an input to the rotating separationsection, a static separation fluid drain configured to capture fluidseparated by the static separation section, and a rotating separationsection fluid drain configured to capture fluid separated by therotating fluid separation section, wherein the static separation fluiddrain and the rotating separation fluid drain are at the same pressure.

One embodiment of the disclosure includes a combined compressor andtwo-stage fluid separation system. The system includes a centrifugalcompressor attached to a driven shaft, a rotating separation sectionattached to the driven shaft and configured to rotate therewith, anoutput of the rotating separation section being in fluid communicationwith an input of the centrifugal compressor, a static separation sectionpositioned longitudinally along an axis of the driven shaft, an input ofthe static separation section being positioned to receive a gas streamand direct the gas stream around a static separation turn positionedradially outward of the rotating separation section and including aseparation turn of between about 150° and 190°, and a rotatingseparation section fluid drain and a static separation section fluiddrain, both drains being contained in a single pressure vessel and beingat the same pressure.

BRIEF DESCRIPTION OF THE DRAWINGS

The present disclosure is best understood from the following detaileddescription when read with the accompanying Figures. It is emphasizedthat, in accordance with the standard practice in the industry, variousfeatures are not drawn to scale. In fact, the dimensions of the variousfeatures may be arbitrarily increased or reduced for clarity ofdiscussion.

FIG. 1 illustrates a partial, sectional view of an exemplary staticseparator assembly of the present disclosure.

FIG. 2 illustrates a sectional view of an exemplary ICS system of thepresent disclosure.

FIG. 3 illustrates a sectional view of the exemplary rotary separationportion of the exemplary ICS system illustrated in FIG. 2.

FIG. 4 illustrates an end sectional view of the exemplary rotaryseparation portion of the exemplary ICS system illustrated in FIG. 2.

FIG. 5 illustrates perspective sectional view of an exemplary integratedstatic and rotary separator system of the disclosure.

FIG. 6 illustrates sectional view of an exemplary integrated static androtary separator system of the disclosure.

DETAILED DESCRIPTION

It is to be understood that the following disclosure describes severalexemplary embodiments for implementing different features, structures,or functions of the invention. Exemplary embodiments of components,arrangements, and configurations are described below to simplify thepresent disclosure; however, these exemplary embodiments are providedmerely as examples and are not intended to limit the scope of theinvention. Additionally, the present disclosure may repeat referencenumerals and/or letters in the various exemplary embodiments and acrossthe Figures provided herein. This repetition is for the purpose ofsimplicity and clarity and does not in itself dictate a relationshipbetween the various exemplary embodiments and/or configurationsdiscussed in the various Figures. Moreover, the formation of a firstfeature over or on a second feature in the description that follows mayinclude embodiments in which the first and second features are formed indirect contact, and may also include embodiments in which additionalfeatures may be formed interposing the first and second features, suchthat the first and second features may not be in direct contact.Finally, the exemplary embodiments presented below may be combined inany combination of ways, i.e., any element from one exemplary embodimentmay be used in any other exemplary embodiment, without departing fromthe scope of the disclosure.

Additionally, certain terms are used throughout the followingdescription and claims to refer to particular components. As one skilledin the art will appreciate, various entities may refer to the samecomponent by different names, and as such, the naming convention for theelements described herein is not intended to limit the scope of theinvention, unless otherwise specifically defined herein. Further, thenaming convention used herein is not intended to distinguish betweencomponents that differ in name but not function. Further, in thefollowing discussion and in the claims, the terms “including” and“comprising” are used in an open-ended fashion, and thus should beinterpreted to mean “including, but not limited to.” All numericalvalues in this disclosure may be exact or approximate values unlessotherwise specifically stated. Accordingly, various embodiments of thedisclosure may deviate from the numbers, values, and ranges disclosedherein without departing from the intended scope. Furthermore, as it isused in the claims or specification, the term “or” is intended toencompass both exclusive and inclusive cases, i.e., “A or B” is intendedto be synonymous with “at least one of A and B,” unless otherwiseexpressly specified herein.

FIG. 1 illustrates an exemplary static separator 1 that may be used inthe combination static and rotary separation system of the presentdisclosure. An inlet duct 2 to the static separation system 1 has afluid entrance 50 that is connected to an inlet pipe 49 and an inletfluid exit 3 that is connected to a separating turn 5. Further, theinlet duct 2 has an outer wall 58 and an inner wall 60, which are spacedapart. The distance between the outer and inner walls 58, 60 defines aninlet width W_(I). At any given horizontal cross-section, the inlet duct2 further defines an inlet radius R_(I), with the inlet radius R_(I)being the distance from a centerline 43 of the static separator 1 to thecenter of the inlet duct 2. As illustrated, the inlet width W_(I)decreases from a maximum at the inlet fluid entrance 50 to a minimum atthe inlet fluid exit 3. Further, the inlet radius R_(I) may varyinversely with the inlet width W_(I), such that the inlet radius R_(I)increases as the inlet width W_(I) decreases. The inlet radius R_(I) hasa maximum inlet radius R_(I) at the inlet fluid exit 3 and a minimuminlet radius R_(I) at the inlet fluid entrance 50. Accordingly, thecross-sectional area through which a fluid may flow, i.e., the flowarea, of the inlet duct 2 at any given horizontal cross-section willgenerally remain substantially constant. Further, the inlet duct 2 mayextend at an angle α until the inlet radius R_(I) reaches a desiredlength, which may be, for example, three times the nominal radius of theinlet pipe 49, at which point the inlet fluid exit 3 of the inlet duct 2may be connected to the separating turn 5.

The separating turn 5 is fluidly connected to the inlet duct 2 at aninlet end 4, and has a gas outlet end 17 that is connected to the outletfluid entrance 66 of the outlet duct 24. Between the inlet end 4 and thegas outlet end 17, the separating turn 5 includes an inner surface 6 andan outer surface 7, with an outer body 8 of the separator 1 providingthe outer surface 7. A gas return channel 45 may be formed around theoutside of the separating turn 5, such that the separating turn 5 isgenerally disposed between the gas return channel 45 and the centerline43. The gas return channel 45 may include a passageway 35, which may beat least partially toroidal around the outside of the separating turn 5,and may terminate at an injection interface 47, which is fluidlyconnected to the separating turn 5, proximate the inlet end 4. In anexemplary embodiment, the gas return channel 45 fluidly connects aliquid outlet 9 to the separating turn 5, and the injection interface 47may be a convergent nozzle or an ejector, to aid in redirecting of anoutflow of gas, as described below.

The separating turn 5 may further include an auxiliary liquid outletchannel 11, which may include a lip 38 extending from the outer surface7 toward the inner surface 6 and located proximate the gas outlet end 17of the separating turn 5. The auxiliary liquid outlet channel 11 mayalso include a liquid passageway 42, which may extend, for example,through the outer body 8 to the liquid outlet 9, thereby fluidlyconnecting the lip 38 with the liquid outlet 9.

The gas outlet end 17 of the separating turn 5 may be connected to theoutlet fluid entrance 66 of the outlet duct 24. In an exemplaryembodiment, the outlet duct 24 may be formed similarly to the inlet duct2. Accordingly, the outlet duct 24 may have an outlet fluid exit 67connected to an outlet pipe 33, and an interior wall 19. The interiorwall 19 may be defined by a radial flow expander 39, which may form aflow expander peak 25, where a flow of fluid through the outlet duct 24flows out into the outlet pipe 33, thereby changing from a flow pathwith a ring-shaped cross-section to one with a circular cross-section.In another exemplary embodiment, the inlet duct 2 is inside the outletduct 24, the radial flow expander 39 may be formed in the inlet duct 2,such that it defines the inner wall 60 of the inlet duct 2. In such anembodiment, the flow expander peak 25 may form the beginning of thechange in the shape of the cross-section of the fluid flow from circularin the inlet pipe 49 to ring-shaped in the inlet duct 2.

The interior wall 19 may be spaced apart from an exterior wall 63 of theoutlet duct 24 to define an outlet duct width W_(O). The outlet ductwidth W_(O) may increase from a minimum outlet duct width W_(O) at theoutlet fluid entrance 66, to a maximum outlet width W_(O) at the outletfluid exit 67. Additionally, the distance from the centerline 43 to themiddle of the outlet duct 24 may define an outlet duct radius R_(O). Inan exemplary embodiment, the outlet duct radius R_(O) may decrease fromthe outlet fluid entrance 66 to the outlet fluid exit 67 in inverseproportion to the increasing outlet width W_(O), such that thehorizontal cross-section of the flow area of the outlet duct 24 remainssubstantially constant throughout.

Applicants note that an exemplary static separator is shown incommonly-assigned U.S. patent application having Publication No.2011/0061536, entitled Improved Density-Based Compact Separator, thecontents of which are hereby incorporated by reference into the presentapplication, to the extent that the incorporated application isconsistent with the present disclosure.

FIG. 2 illustrates an exemplary rotary separator and compressorcombination, which may be generally referred to as an integratedcompression system or ICS. The exemplary ICS system briefly describedherein is further detailed in commonly-owned U.S. patent applicationhaving Ser. No. 60/778,688 and PCT Patent Application having Serial No.PCT/US2007/005489, entitled Multiphase Processing Device, which wasfirst filed on Mar. 3, 2006; the contents of this commonly-ownedapplication are hereby incorporated by reference into the presentapplication, to the extent that the incorporated subject matter isconsistent with the present disclosure. Additionally, FIG. 3 illustratesa sectional view of the exemplary rotary separation portion of theexemplary ICS system illustrated in FIG. 2, and FIG. 4 illustrates anend sectional view of the exemplary rotary separation portion of theexemplary ICS system illustrated in FIG. 2. Both of these figures arefrom the prior application that is incorporated by reference, and assuch, further description of the specifics of these figures is found inthe incorporated application.

The exemplary ICS system 10 is configured to process a multiphase fluidstream F that includes a mixture of a gas G and a liquid L, andgenerally includes a housing 12 having an interior chamber 13, arotating separator 14, a multistage compressor 16, and a pump 18(optional) or a liquid collector (not shown), each of which aregenerally disposed within the same housing or chamber 13. The housing 12has an inlet 22 fluidly connected with the interior chamber 13 andfluidly connectable with a source multiphase stream S_(F), and first andsecond outlets 24A, 24B.

The rotating separator 14 of the ICS system 10 is fluidly coupled withthe housing inlet 22, such that the fluid stream F flows generally tothe rotating separator 14. The rotating separator 14 is configured toseparate the fluid stream F into a substantially gaseous portion G and asubstantially liquid portion L. The compressor 16 is fluidly coupledwith the rotating separator 14 such that the substantially gaseousportion G output from the rotating separator 14 flows into thecompressor 16 for compression before being discharged from thecompressor at an outlet 24A.

Further, the optional pump 18 has an inlet 28 fluidly coupled with therotating separator 14, and is preferably spaced therefrom, such that thestream liquid portion L flows at least partially by gravity orcentrifugal force from the rotating separator 14 to the pump inlet 28.However, the separator 14 and/or pump 18 may be configured such that thesubstantially liquid portion L flows substantially by suction generatedby the pump 18, particularly when the rotating separator 14 and the pump18 are horizontally-spaced, or in any other appropriate manner. The pump18 is configured to pressurize the liquid portion L of the flow stream Fand to discharge the pressurized liquid portion L through the housingsecond or “liquid” outlet 24B. The ICS system 10 may instead have aliquid collector (not shown) disposed generally beneath or otherwiseproximate the compressor 16 and fluidly coupled with the rotatingseparator 14 and with the housing second outlet 24B, the collector 20having a chamber 21 configured to contain a quantity or “accumulatedvolume” of the liquid portions L.

The ICS system 10 also generally includes a drive shaft 30 extendinggenerally through the housing chamber 13 and being rotatable about acentral axis 31. Each one of the rotating separator 14, the compressor16, and the optional pump 18 having at least one rotatable member 40,64, and 84, respectively, connected with the shaft 30 and spaced apartvertically along the central axis 31. As such, rotation of the driveshaft 30 about the axis 31 generally operates each one of the separator14, the compressor 16 and the pump 18. The ICS system 10 may furtherinclude a drive motor (not shown) connected with the shaft 30 andconfigured to rotate the shaft 30 about the central axis 31, the motorgenerally being mounted to one end 12 a or 12 b of the housing 13.

The rotating separator 14 is configured to direct liquid extracted fromthe fluid stream radially-outwardly toward a housing inner surface 25,such that liquid portions L flow into a liquid flow channel 34 andthereafter flow at least partially by gravity or other fluid drivingforce to the optional pump inlet 28. As illustrated in FIGS. 3-6, therotating separator 14 may include a body 40 rotatable about a centralaxis 41, the separator body 40 having a first and second end 40 a, 40 b,respectively. The first or “upper” body end 40 a has a first or “streaminlet” opening 42 fluidly coupled with the housing inlet 22 so as toreceive the fluid stream F, and the second or “lower” body end 40 b hasa second or “gas outlet” opening 44 fluidly coupled with the compressor16. An inner separation surface 46 extends circumferentially about theaxis 41 and generally between the body first and second ends 40 a, 40 b.Further, the separation surface 46 defines a separation chamber 48 andis angled radially-outward toward the body first end 40 a. With thisstructure, as the separator body 40 rotates about the axis 41, liquidportions L of the fluid stream F contact the inner separation surface 46are directed away from the body axis 41 and toward, and beyond, the bodyfirst end 40 a. In other words, centrifugal force generated by rotationof the separator 14 causes the relatively-heavier, liquid portions L(compared to the gas portion) contacting the rotating inner separationsurface 46 to move upwardly and outwardly the along the angled innersurface 46 until the liquid portions are projected or “slung” from thebody upper end 40 a in a spiral path toward the housing inner surface25. As such, the liquid portions L are directed to flow back out throughthe body first opening 42 while a remainder of the fluid stream F, i.e.,the substantially gaseous portions G, flows in the downward direction d2through the body second opening 44, and thereafter into the compressor16.

The separator 14 may further include an outer separation surface 50extending circumferentially about the body axis 41 and generally betweenthe body first and second ends 40 a, 40 b. As with the inner surface 46,the outer separation surface 50 is angled radially-outward in thedirection toward the body first end 40 a. As such, as the separator body40 rotates about the axis 41, liquid portions L of the fluid stream Fcontacting the outer separation surface 50 are directed generallyradially outward away from the body axis 41 and generally axially towardthe body first end 40 so as to be directed generally toward the housinginner surface 25. In other words, centrifugal forces cause therelatively heavier liquid portions L contacting the rotating outerseparation surface 50 to slide or move upwardly and outwardly the alongangled outer separation surface 50 until being projected/slung from theseparator body upper end 40 a in a generally spiral path toward thehousing inner surface 25.

With the basic structure described above, operation of the ICS system 10of the present disclosure may be appreciated. A multiphase fluid streamF enters the housing 12 through the housing inlet 22 and flows into aplenum chamber 56, swirls about and flows into the rotating separator14. Liquid portions L are separated from the remaining, substantiallygaseous portions G of the fluid stream F, and are directed into theliquid flow passage 34. Generally simultaneously, the gaseous portions Gflow into the compressor inlet 26 and are pressurized or compressed suchthat the gas pressure is incrementally increased as the gas portions Gflow through each compressor stage 66. The pressurized gas portions Gpare discharged from the compressor 16 and flow out the housing throughthe housing gas outlet 24A.

The separated liquid portions L entering the liquid flow passage 34 flowby gravity (and suction) through a passage vertical portion 36, and thusaround the compressor 16, and then through the passage horizontalportion 37 beneath the compressor 16 and into the optional pump inlet28. The optional centrifugal pump 80 then pressurizes the liquidportions Lp as the portions Lp are accelerated radially outwardly by theimpeller 84, and the pressurized liquid portions Lp flow out of thehousing 12 through the liquid outlet 24B. The pressurized gas and liquidportions Gp, Lp may be merged or remixed in a common outlet pipe 23connected with both of the housing outlets 24A, 24B, such that thepressurized fluid stream Fp is further processed or utilized, but thetwo pressurized flows Gp, Lp may alternatively remain distinct so as tobe thereafter separately processed or utilized.

Applicants note that although the exemplary ICS 10 described herein isshown as a vertically oriented system, i.e., the common shaft 30 of therotating separator 14 and compressor 16 is vertically oriented, thepresent disclosure is not limited to any particular orientation. Assuch, the present disclosure includes fluid separation and compressionsystems where the common shaft 30 is generally horizontally oriented.Other exemplary rotary separation systems include those disclosed incommonly-owned U.S. Provisional Patent Application Ser. No. 60/846,300and the following Utility application Ser. No. 12/441,804; and commonlyowned U.S. Provisional Patent Application Ser. No. 60/826,876 and thefollowing Utility application Ser. No. 12/442,863. Each of the abovenoted commonly owned patent applications are incorporated by referencein their entirety into the present disclosure, to the extent that theseprior disclosures are consistent with the present disclosure.

FIG. 5 illustrates perspective, sectional view of an exemplaryintegrated static and rotary separator system 500 of the disclosure, andFIG. 6 illustrates sectional view of an exemplary integrated static androtary separator system 500 of the disclosure. The integrated separator500 generally includes a static separation section 502 and a rotatingseparation section 504, with the static separation section 502 beingbolted onto or otherwise attached to the front end of the rotatingseparation section 504. The attachment may include bolting the staticseparation section 502 directly to an inlet flange (not shown) of therotating separation section. One advantage of attaching a staticseparator to the front end of a rotating separator is that the capacityof the rotating separator can be substantially increased. For example,by positioning a static separator upstream of a rotating separator, thestatic separator can function to coarse-separate fluids from theincoming gas stream, with coarse-separation including removing a portionof the fluid from the stream (generally the higher-density fluids areremoved by the static separation). Thus, the gas stream entering therotating separator has less liquid mass to separate, and as such, therotating separator 504 is able to more efficiently separate theremaining liquids from the incoming (already coarse-separated) stream.The end result of adding a static separator to a rotating separator is asubstantial increase in the separation efficiency, as the rotatingseparator does not get bogged down with coarse separation and is able toefficiently separate higher-density fluids from the incoming stream.Applicants note that the static separator may also be combined with therotating separator 504 in a common casing (without the bolting or otherattachment limitation).

The static section 502 of the integrated separator 500 includes an inlet506 configured to receive the incoming fluid stream (containing, e.g.,liquids and gases therein) for separation. The fluid stream enters theintegrated separator 500 at the inlet 506 and is directedradially-outward (away from a central axis of the separator 500) towarda separation turn 508. The fluid stream is directed around theseparation turn 508, as described with respect to FIG. 1, and as aresult of the centrifugal force, coarse separation of liquids from thefluid stream is conducted. The coarse separation pulls heavier fluidsoutward toward the outer wall of the separation turn 508, while the lessdense gas, which may contain some liquids therein, continues to travelradially-inward (toward the central axis of the separator 500) through aconduit that connects the separation turn 508 to an inlet 510 of therotary separation section 504. The coarsely separated fluid that isseparated by the turn 508 is collected in a static separation chamber521 and may be drained or otherwise removed therefrom as desired.

The separation turn 508 may be structurally and functionally similar orthe same as the separating turn 5 described above with respect to FIG.1, and may include an annular fluid path having a high-velocity gasstream turn that includes at least a 130° flow patch directionchange/turn that is configured to coarse-separate heavier liquids in thegas stream from the lighter gas portion of the stream. In oneembodiment, the velocity (traveling speed of the gas through theassociated conduit) of the fluid stream does not significantly decreaseas the fluid stream travels around the separation turn 5. Thus the speedis maintained at a level sufficient to provide the centrifugal forcenecessary to coarse-separate liquids from the fluid stream as the fluidstream passes around the turn 5. The separating turn 5 may form anyangle sufficient to generate the centrifugal force required to separatethe liquids in the incoming fluid stream. In exemplary embodiments, theturning angle may be about 180°, between about 150 and 190°, betweenabout 100° and about 130°, between about 125° and about 150°, or betweenabout 100° and about 190°.

The fluid stream exiting the static separation section 502 is directedto the inlet 510 of the rotary separation section 504. The rotaryseparator 512, as detailed above with respect to FIGS. 2-4, generallyspins the gas stream via a driven separation drum to separate theremaining fluids from the gas stream. The output 514 of the rotaryseparation section 504 may then be communicated to a compressor (e.g.,compressor 16, above) for compression without significant liquid beingcontained in the gas to be compressed. Additionally, liquid separatedfrom the fluid stream is expelled via a fluid drain 520 of the rotaryseparation section 504 and is collected in a rotary separation chamber518, which is in fluid communication with the static separation chamber521. As such, the fluid drained from the rotary separator section 504 isat the same pressure as the fluid drained from the static separationsection 502. This provides a single pressure vessel configuration forthe respective drains for the separation sections, which provides asubstantial reduction in cost and maintenance.

Applicants contemplate that the static separator may be an aftermarketadd-on to an existing rotary separator assembly to provide foradditional separation capacity. In this embodiment, the stationaryseparator may be bolted or otherwise attached to the input side of therotary separator and be used to pre-separate or coarse separate fluidsfrom the incoming gas stream to increase the efficiency of the rotatingseparator. It should be noted that this increase in separationefficiency requires no input power, as the static separator is not shaftdriven. Additionally, the static separator is generally configured toadd minimal shaft or casing length to the overall apparatus, as theseparation curve discussed above is radially outward from the shaft, andfurther, as shown in FIGS. 5 and 6, the separation curve includes anaxial component, i.e., the gas stream is directed both radially outwardand axially around the separation curve. Thus, the separation curve isgenerally at least partially positioned radially outward of the rotaryseparation drum, which adds minimal shaft or casing length to theoverall separation assembly.

The foregoing has outlined features of several embodiments so that thoseskilled in the art may better understand the present disclosure. Thoseskilled in the art should appreciate that they may readily use thepresent disclosure as a basis for designing or modifying other processesand structures for carrying out the same purposes and/or achieving thesame advantages of the embodiments introduced herein. Those skilled inthe art should also realize that such equivalent constructions do notdepart from the spirit and scope of the present disclosure, and thatthey may make various changes, substitutions and alterations hereinwithout departing from the spirit and scope of the present disclosure.

We claim:
 1. A combined static and dynamic separation system,comprising: a compressor having a rotary shaft; a rotating separationsystem comprising a rotating separation drum coupled with the rotaryshaft and configured to rotate with the rotary shaft; a staticseparation system disposed axially-forwardly, upstream of the rotatingseparation system, the static separation system comprising: an axialinlet of the static separation system; a static separation curve fluidlycoupled with and disposed radially outward of the axial inlet of thestatic separation system; and an outlet of the static separation systemfluidly coupled with an inlet of the rotating separation system; astatic separation drain system configured to receive at least a portionof a fluid separated by the static separation system; and a rotatingseparation drain system configured to receive at least a portion of afluid separated by the rotating separation system.
 2. The combinedstatic and dynamic separation system of claim 1, wherein the staticseparation curve has a turn angle between about 100 degrees and about190 degrees.
 3. The combined static and dynamic separation system ofclaim 2, wherein the turn angle of the static separation curve isbetween about 150 degrees and about 190 degrees.
 4. The combined staticand dynamic separation system of claim 1, wherein the static separationcurve is disposed radially outward of the inlet of the rotatingseparation system.
 5. The combined static and dynamic separation systemof claim 1, wherein the static separation system comprises a staticseparation housing coupled with a front end portion of the rotatingseparation system.
 6. The combined static and dynamic separation systemof claim 1, wherein the static separation drain system is fluidlycoupled with the rotating separation drain system.
 7. The combinedstatic and dynamic separation system of claim 6, wherein the staticseparation drain system and the rotating separation drain system aredisposed in a common pressure vessel.
 8. A multistage separation system,comprising: a compressor coupled with a rotary shaft; a rotatingseparation system coupled to the rotary shaft and configured to rotatetherewith; and a static separation system disposed axially-forwardly,upstream of the rotating separation system, the static separation systemincluding a static separation housing disposed axially along alongitudinal axis of the rotary shaft, the static separation housing atleast partially defining an axial inlet of the static separation systemaligned with the longitudinal axis, a static separation curve, and afluid path extending radially outward from the axial inlet of the staticseparation system to the static separation curve to fluidly couple theaxial inlet of the static separation system with the static separationcurve, wherein the static separation curve has an outlet fluidly coupledwith an inlet of the rotating separation system.
 9. The multistageseparation system of claim 8, wherein the outlet of the staticseparation curve is disposed radially outward of the inlet of therotating separation system.
 10. The multistage separation system ofclaim 8, wherein the static separation system further comprises a staticseparation chamber.
 11. The multistage separation system of claim 10,wherein the rotating separation system further comprises a fluid drainoutlet fluidly coupled with the static separation chamber.
 12. Themultistage separation system of claim 11, wherein the fluid drain outletand the static separation chamber are disposed in a common pressurevessel.